IfModifiedSince Property

A date determining the maximum age of the desired document.

Syntax

 json.getIfModifiedSince([callback])
 json.setIfModifiedSince( ifModifiedSince, [callback])

Default Value

""

Callback

The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).

The callback for the getIfModifiedSince([callback]) method is defined as:

function(err, data){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'data' is the value returned by the method.

The callback for the setIfModifiedSince([callback]) method is defined as:

function(err){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'err' has 2 properties which hold detailed information:

err.code
err.message

Remarks

If this property contains a non-empty string, an If-Modified-Since HTTP header is added to the request. The value of this header is used to make the HTTP request conditional: if the requested documented has not been modified since the time specified in the field, a copy of the document will not be returned from the server; instead, a 304 (not modified) response will be returned by the server and the class fails with an error

The format of the date value for IfModifiedSince is detailed in the HTTP specs. An example is Sat, 29 Oct 1994 19:43:31 GMT.

This property is not available at design time.

Data Type

String